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linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c

@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2024 Hisilicon Limited.
+
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/minmax.h>
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+#include "dp_comm.h"
+#include "dp_reg.h"
+#include "dp_hw.h"
+
+#define HIBMC_AUX_CMD_REQ_LEN		GENMASK(7, 4)
+#define HIBMC_AUX_CMD_ADDR		GENMASK(27, 8)
+#define HIBMC_AUX_CMD_I2C_ADDR_ONLY	BIT(28)
+#define HIBMC_BYTES_IN_U32		4
+#define HIBMC_AUX_I2C_WRITE_SUCCESS	0x1
+#define HIBMC_DP_MIN_PULSE_NUM		0x9
+#define BITS_IN_U8			8
+
+static inline void hibmc_dp_aux_reset(struct hibmc_dp_dev *dp)
+{
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_DPTX_RST_CTRL, HIBMC_DP_CFG_AUX_RST_N, 0x0);
+	usleep_range(10, 15);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_DPTX_RST_CTRL, HIBMC_DP_CFG_AUX_RST_N, 0x1);
+}
+
+static void hibmc_dp_aux_read_data(struct hibmc_dp_dev *dp, u8 *buf, u8 size)
+{
+	u32 reg_num;
+	u32 value;
+	u32 num;
+	u8 i, j;
+
+	reg_num = DIV_ROUND_UP(size, HIBMC_BYTES_IN_U32);
+	for (i = 0; i < reg_num; i++) {
+		/* number of bytes read from a single register */
+		num = min(size - i * HIBMC_BYTES_IN_U32, HIBMC_BYTES_IN_U32);
+		value = readl(dp->base + HIBMC_DP_AUX_RD_DATA0 + i * HIBMC_BYTES_IN_U32);
+		/* convert the 32-bit value of the register to the buffer. */
+		for (j = 0; j < num; j++)
+			buf[i * HIBMC_BYTES_IN_U32 + j] = value >> (j * BITS_IN_U8);
+	}
+}
+
+static void hibmc_dp_aux_write_data(struct hibmc_dp_dev *dp, u8 *buf, u8 size)
+{
+	u32 reg_num;
+	u32 value;
+	u32 num;
+	u8 i, j;
+
+	reg_num = DIV_ROUND_UP(size, HIBMC_BYTES_IN_U32);
+	for (i = 0; i < reg_num; i++) {
+		/* number of bytes written to a single register */
+		num = min_t(u8, size - i * HIBMC_BYTES_IN_U32, HIBMC_BYTES_IN_U32);
+		value = 0;
+		/* obtain the 32-bit value written to a single register. */
+		for (j = 0; j < num; j++)
+			value |= buf[i * HIBMC_BYTES_IN_U32 + j] << (j * BITS_IN_U8);
+		/* writing data to a single register */
+		writel(value, dp->base + HIBMC_DP_AUX_WR_DATA0 + i * HIBMC_BYTES_IN_U32);
+	}
+}
+
+static u32 hibmc_dp_aux_build_cmd(const struct drm_dp_aux_msg *msg)
+{
+	u32 aux_cmd = msg->request;
+
+	if (msg->size)
+		aux_cmd |= FIELD_PREP(HIBMC_AUX_CMD_REQ_LEN, (msg->size - 1));
+	else
+		aux_cmd |= FIELD_PREP(HIBMC_AUX_CMD_I2C_ADDR_ONLY, 1);
+
+	aux_cmd |= FIELD_PREP(HIBMC_AUX_CMD_ADDR, msg->address);
+
+	return aux_cmd;
+}
+
+/* ret >= 0, ret is size; ret < 0, ret is err code */
+static int hibmc_dp_aux_parse_xfer(struct hibmc_dp_dev *dp, struct drm_dp_aux_msg *msg)
+{
+	u32 buf_data_cnt;
+	u32 aux_status;
+
+	aux_status = readl(dp->base + HIBMC_DP_AUX_STATUS);
+	msg->reply = FIELD_GET(HIBMC_DP_CFG_AUX_STATUS, aux_status);
+
+	if (aux_status & HIBMC_DP_CFG_AUX_TIMEOUT)
+		return -ETIMEDOUT;
+
+	/* only address */
+	if (!msg->size)
+		return 0;
+
+	if (msg->reply != DP_AUX_NATIVE_REPLY_ACK)
+		return -EIO;
+
+	buf_data_cnt = FIELD_GET(HIBMC_DP_CFG_AUX_READY_DATA_BYTE, aux_status);
+
+	switch (msg->request) {
+	case DP_AUX_NATIVE_WRITE:
+		return msg->size;
+	case DP_AUX_I2C_WRITE | DP_AUX_I2C_MOT:
+		if (buf_data_cnt == HIBMC_AUX_I2C_WRITE_SUCCESS)
+			return msg->size;
+		else
+			return FIELD_GET(HIBMC_DP_CFG_AUX, aux_status);
+	case DP_AUX_NATIVE_READ:
+	case DP_AUX_I2C_READ | DP_AUX_I2C_MOT:
+		buf_data_cnt--;
+		if (buf_data_cnt != msg->size) {
+			/* only the successful part of data is read */
+			return -EBUSY;
+		}
+
+		/* all data is successfully read */
+		hibmc_dp_aux_read_data(dp, msg->buffer, msg->size);
+		return msg->size;
+	default:
+		return -EINVAL;
+	}
+}
+
+/* ret >= 0 ,ret is size; ret < 0, ret is err code */
+static ssize_t hibmc_dp_aux_xfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
+{
+	struct hibmc_dp *dp_priv = container_of(aux, struct hibmc_dp, aux);
+	struct hibmc_dp_dev *dp = dp_priv->dp_dev;
+	u32 aux_cmd;
+	int ret;
+	u32 val; /* val will be assigned at the beginning of readl_poll_timeout function */
+
+	writel(0, dp->base + HIBMC_DP_AUX_WR_DATA0);
+	writel(0, dp->base + HIBMC_DP_AUX_WR_DATA1);
+	writel(0, dp->base + HIBMC_DP_AUX_WR_DATA2);
+	writel(0, dp->base + HIBMC_DP_AUX_WR_DATA3);
+
+	hibmc_dp_aux_write_data(dp, msg->buffer, msg->size);
+
+	aux_cmd = hibmc_dp_aux_build_cmd(msg);
+	writel(aux_cmd, dp->base + HIBMC_DP_AUX_CMD_ADDR);
+
+	/* enable aux transfer */
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_REQ, 0x1);
+	ret = readl_poll_timeout(dp->base + HIBMC_DP_AUX_REQ, val,
+				 !(val & HIBMC_DP_CFG_AUX_REQ), 50, 5000);
+	if (ret) {
+		hibmc_dp_aux_reset(dp);
+		return ret;
+	}
+
+	return hibmc_dp_aux_parse_xfer(dp, msg);
+}
+
+void hibmc_dp_aux_init(struct hibmc_dp *dp)
+{
+	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
+	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_TIMER_TIMEOUT, 0x1);
+	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_MIN_PULSE_NUM,
+				 HIBMC_DP_MIN_PULSE_NUM);
+
+	dp->aux.transfer = hibmc_dp_aux_xfer;
+	dp->aux.name = "HIBMC DRM dp aux";
+	dp->aux.drm_dev = dp->drm_dev;
+	drm_dp_aux_init(&dp->aux);
+	dp->dp_dev->aux = &dp->aux;
+}

linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h

@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_COMM_H
+#define DP_COMM_H
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <drm/display/drm_dp_helper.h>
+
+#include "dp_hw.h"
+
+#define HIBMC_DP_LANE_NUM_MAX 2
+
+struct hibmc_link_status {
+	bool clock_recovered;
+	bool channel_equalized;
+};
+
+struct hibmc_link_cap {
+	u8 link_rate;
+	u8 lanes;
+};
+
+struct hibmc_dp_link {
+	struct hibmc_link_status status;
+	u8 train_set[HIBMC_DP_LANE_NUM_MAX];
+	struct hibmc_link_cap cap;
+};
+
+struct hibmc_dp_dev {
+	struct drm_dp_aux *aux;
+	struct drm_device *dev;
+	void __iomem *base;
+	struct mutex lock; /* protects concurrent RW in hibmc_dp_reg_write_field() */
+	struct hibmc_dp_link link;
+	u8 dpcd[DP_RECEIVER_CAP_SIZE];
+	u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
+	struct drm_dp_desc desc;
+	bool is_branch;
+	int hpd_status;
+	void __iomem *serdes_base;
+};
+
+#define dp_field_modify(reg_value, mask, val)				\
+	do {								\
+		(reg_value) &= ~(mask);					\
+		(reg_value) |= FIELD_PREP(mask, val);			\
+	} while (0)							\
+
+#define hibmc_dp_reg_write_field(dp, offset, mask, val)			\
+	do {								\
+		typeof(dp) _dp = dp;					\
+		typeof(_dp->base) addr = (_dp->base + (offset));	\
+		mutex_lock(&_dp->lock);					\
+		u32 reg_value = readl(addr);				\
+		dp_field_modify(reg_value, mask, val);			\
+		writel(reg_value, addr);				\
+		mutex_unlock(&_dp->lock);				\
+	} while (0)
+
+void hibmc_dp_aux_init(struct hibmc_dp *dp);
+int hibmc_dp_link_training(struct hibmc_dp_dev *dp);
+int hibmc_dp_serdes_init(struct hibmc_dp_dev *dp);
+int hibmc_dp_serdes_rate_switch(u8 rate, struct hibmc_dp_dev *dp);
+int hibmc_dp_serdes_set_tx_cfg(struct hibmc_dp_dev *dp, u8 train_set[HIBMC_DP_LANE_NUM_MAX]);
+void hibmc_dp_update_caps(struct hibmc_dp_dev *dp);
+
+#endif

linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_CONFIG_H
+#define DP_CONFIG_H
+
+#define HIBMC_DP_BPP			24
+#define HIBMC_DP_SYMBOL_PER_FCLK	4
+#define HIBMC_DP_MSA1			0x20
+#define HIBMC_DP_MSA2			0x845c00
+#define HIBMC_DP_OFFSET			0x1e0000
+#define HIBMC_DP_HDCP			0x2
+#define HIBMC_DP_INT_RST		0xffff
+#define HIBMC_DP_DPTX_RST		0x3ff
+#define HIBMC_DP_CLK_EN			0x7
+#define HIBMC_DP_SYNC_EN_MASK		0x3
+#define HIBMC_DP_LINK_RATE_CAL		27
+#define HIBMC_DP_SYNC_DELAY(lanes)	((lanes) == 0x2 ? 86 : 46)
+#define HIBMC_DP_INT_ENABLE		0xc
+/* HIBMC_DP_LINK_RATE_CAL * 10000 * 80% = 216000 */
+#define DP_MODE_VALI_CAL		216000
+
+#endif

linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c

@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2024 Hisilicon Limited.
+
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/delay.h>
+#include "dp_config.h"
+#include "dp_comm.h"
+#include "dp_reg.h"
+#include "dp_hw.h"
+
+static void hibmc_dp_set_tu(struct hibmc_dp_dev *dp, struct drm_display_mode *mode)
+{
+	u32 tu_symbol_frac_size;
+	u32 tu_symbol_size;
+	u32 rate_ks;
+	u8 lane_num;
+	u32 value;
+	u32 bpp;
+
+	lane_num = dp->link.cap.lanes;
+	if (lane_num == 0) {
+		drm_err(dp->dev, "set tu failed, lane num cannot be 0!\n");
+		return;
+	}
+
+	bpp = HIBMC_DP_BPP;
+	rate_ks = dp->link.cap.link_rate * HIBMC_DP_LINK_RATE_CAL;
+	value = (mode->clock * bpp * 5) / (61 * lane_num * rate_ks);
+
+	if (value % 10 == 9) { /* 9 carry */
+		tu_symbol_size = value / 10 + 1;
+		tu_symbol_frac_size = 0;
+	} else {
+		tu_symbol_size = value / 10;
+		tu_symbol_frac_size = value % 10 + 1;
+	}
+
+	drm_dbg_dp(dp->dev, "tu value: %u.%u value: %u\n",
+		   tu_symbol_size, tu_symbol_frac_size, value);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_PACKET,
+				 HIBMC_DP_CFG_STREAM_TU_SYMBOL_SIZE, tu_symbol_size);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_PACKET,
+				 HIBMC_DP_CFG_STREAM_TU_SYMBOL_FRAC_SIZE, tu_symbol_frac_size);
+}
+
+static void hibmc_dp_set_sst(struct hibmc_dp_dev *dp, struct drm_display_mode *mode)
+{
+	u32 hblank_size;
+	u32 htotal_size;
+	u32 htotal_int;
+	u32 hblank_int;
+	u32 fclk; /* flink_clock */
+
+	fclk = dp->link.cap.link_rate * HIBMC_DP_LINK_RATE_CAL;
+
+	/* Considering the effect of spread spectrum, the value may be deviated.
+	 * The coefficient (0.9947) is used to offset the deviation.
+	 */
+	htotal_int = mode->htotal * 9947 / 10000;
+	htotal_size = htotal_int * fclk / (HIBMC_DP_SYMBOL_PER_FCLK * (mode->clock / 1000));
+
+	hblank_int = mode->htotal - mode->hdisplay - mode->hdisplay * 53 / 10000;
+	hblank_size = hblank_int * fclk * 9947 /
+		      (mode->clock * 10 * HIBMC_DP_SYMBOL_PER_FCLK);
+
+	drm_dbg_dp(dp->dev, "h_active %u v_active %u htotal_size %u hblank_size %u",
+		   mode->hdisplay, mode->vdisplay, htotal_size, hblank_size);
+	drm_dbg_dp(dp->dev, "flink_clock %u pixel_clock %d", fclk, mode->clock / 1000);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_HORIZONTAL_SIZE,
+				 HIBMC_DP_CFG_STREAM_HTOTAL_SIZE, htotal_size);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_HORIZONTAL_SIZE,
+				 HIBMC_DP_CFG_STREAM_HBLANK_SIZE, hblank_size);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_PACKET,
+				 HIBMC_DP_CFG_STREAM_SYNC_CALIBRATION,
+				 HIBMC_DP_SYNC_DELAY(dp->link.cap.lanes));
+}
+
+static void hibmc_dp_link_cfg(struct hibmc_dp_dev *dp, struct drm_display_mode *mode)
+{
+	u32 timing_delay;
+	u32 vblank;
+	u32 hstart;
+	u32 vstart;
+
+	vblank = mode->vtotal - mode->vdisplay;
+	timing_delay = mode->htotal - mode->hsync_start;
+	hstart = mode->htotal - mode->hsync_start;
+	vstart = mode->vtotal - mode->vsync_start;
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_TIMING_GEN_CONFIG0,
+				 HIBMC_DP_CFG_TIMING_GEN0_HBLANK, mode->htotal - mode->hdisplay);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_TIMING_GEN_CONFIG0,
+				 HIBMC_DP_CFG_TIMING_GEN0_HACTIVE, mode->hdisplay);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_TIMING_GEN_CONFIG2,
+				 HIBMC_DP_CFG_TIMING_GEN0_VBLANK, vblank);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_TIMING_GEN_CONFIG2,
+				 HIBMC_DP_CFG_TIMING_GEN0_VACTIVE, mode->vdisplay);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_TIMING_GEN_CONFIG3,
+				 HIBMC_DP_CFG_TIMING_GEN0_VFRONT_PORCH,
+				 mode->vsync_start - mode->vdisplay);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CONFIG0,
+				 HIBMC_DP_CFG_STREAM_HACTIVE, mode->hdisplay);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CONFIG0,
+				 HIBMC_DP_CFG_STREAM_HBLANK, mode->htotal - mode->hdisplay);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CONFIG2,
+				 HIBMC_DP_CFG_STREAM_HSYNC_WIDTH,
+				 mode->hsync_end - mode->hsync_start);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CONFIG1,
+				 HIBMC_DP_CFG_STREAM_VACTIVE, mode->vdisplay);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CONFIG1,
+				 HIBMC_DP_CFG_STREAM_VBLANK, vblank);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CONFIG3,
+				 HIBMC_DP_CFG_STREAM_VFRONT_PORCH,
+				 mode->vsync_start - mode->vdisplay);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CONFIG3,
+				 HIBMC_DP_CFG_STREAM_VSYNC_WIDTH,
+				 mode->vsync_end - mode->vsync_start);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_MSA0,
+				 HIBMC_DP_CFG_STREAM_VSTART, vstart);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_MSA0,
+				 HIBMC_DP_CFG_STREAM_HSTART, hstart);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CTRL, HIBMC_DP_CFG_STREAM_VSYNC_POLARITY,
+				 mode->flags & DRM_MODE_FLAG_PVSYNC ? 1 : 0);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CTRL, HIBMC_DP_CFG_STREAM_HSYNC_POLARITY,
+				 mode->flags & DRM_MODE_FLAG_PHSYNC ? 1 : 0);
+
+	/* MSA mic 0 and 1 */
+	writel(HIBMC_DP_MSA1, dp->base + HIBMC_DP_VIDEO_MSA1);
+	writel(HIBMC_DP_MSA2, dp->base + HIBMC_DP_VIDEO_MSA2);
+
+	hibmc_dp_set_tu(dp, mode);
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CTRL, HIBMC_DP_CFG_STREAM_RGB_ENABLE, 0x1);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CTRL, HIBMC_DP_CFG_STREAM_VIDEO_MAPPING, 0);
+
+	/* divide 2: up even */
+	if (timing_delay % 2)
+		timing_delay++;
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_TIMING_MODEL_CTRL,
+				 HIBMC_DP_CFG_PIXEL_NUM_TIMING_MODE_SEL1, timing_delay);
+
+	hibmc_dp_set_sst(dp, mode);
+}
+
+int hibmc_dp_hw_init(struct hibmc_dp *dp)
+{
+	struct drm_device *drm_dev = dp->drm_dev;
+	struct hibmc_dp_dev *dp_dev;
+	int ret;
+
+	dp_dev = devm_kzalloc(drm_dev->dev, sizeof(struct hibmc_dp_dev), GFP_KERNEL);
+	if (!dp_dev)
+		return -ENOMEM;
+
+	mutex_init(&dp_dev->lock);
+
+	dp->dp_dev = dp_dev;
+
+	dp_dev->dev = drm_dev;
+	dp_dev->base = dp->mmio + HIBMC_DP_OFFSET;
+
+	hibmc_dp_aux_init(dp);
+
+	ret = hibmc_dp_serdes_init(dp_dev);
+	if (ret)
+		return ret;
+
+	dp_dev->link.cap.lanes = 0x2;
+	dp_dev->link.cap.link_rate = DP_LINK_BW_8_1;
+
+	/* int init */
+	writel(0, dp_dev->base + HIBMC_DP_INTR_ENABLE);
+	writel(HIBMC_DP_INT_RST, dp_dev->base + HIBMC_DP_INTR_ORIGINAL_STATUS);
+	/* clr colorbar */
+	writel(0, dp_dev->base + HIBMC_DP_COLOR_BAR_CTRL);
+	/* rst */
+	writel(0, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
+	usleep_range(30, 50);
+	/* de-rst */
+	writel(HIBMC_DP_DPTX_RST, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
+	/* hdcp data */
+	writel(HIBMC_DP_HDCP, dp_dev->base + HIBMC_DP_HDCP_CFG);
+	/* clock enable */
+	writel(HIBMC_DP_CLK_EN, dp_dev->base + HIBMC_DP_DPTX_CLK_CTRL);
+
+	return 0;
+}
+
+void hibmc_dp_enable_int(struct hibmc_dp *dp)
+{
+	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
+
+	writel(HIBMC_DP_INT_ENABLE, dp_dev->base + HIBMC_DP_INTR_ENABLE);
+}
+
+void hibmc_dp_disable_int(struct hibmc_dp *dp)
+{
+	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
+
+	writel(0, dp_dev->base + HIBMC_DP_INTR_ENABLE);
+	writel(HIBMC_DP_INT_RST, dp_dev->base + HIBMC_DP_INTR_ORIGINAL_STATUS);
+}
+
+void hibmc_dp_hpd_cfg(struct hibmc_dp *dp)
+{
+	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
+
+	hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
+	hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_TIMER_TIMEOUT, 0x1);
+	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_MIN_PULSE_NUM, 0x9);
+	writel(HIBMC_DP_HDCP, dp_dev->base + HIBMC_DP_HDCP_CFG);
+	writel(0, dp_dev->base + HIBMC_DP_INTR_ENABLE);
+	writel(HIBMC_DP_INT_RST, dp_dev->base + HIBMC_DP_INTR_ORIGINAL_STATUS);
+	writel(HIBMC_DP_INT_ENABLE, dp_dev->base + HIBMC_DP_INTR_ENABLE);
+	writel(HIBMC_DP_DPTX_RST, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
+	writel(HIBMC_DP_CLK_EN, dp_dev->base + HIBMC_DP_DPTX_CLK_CTRL);
+}
+
+void hibmc_dp_display_en(struct hibmc_dp *dp, bool enable)
+{
+	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
+
+	if (enable) {
+		hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_VIDEO_CTRL, BIT(0), 0x1);
+		writel(HIBMC_DP_SYNC_EN_MASK, dp_dev->base + HIBMC_DP_TIMING_SYNC_CTRL);
+		hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_DPTX_GCTL0, BIT(10), 0x1);
+		writel(HIBMC_DP_SYNC_EN_MASK, dp_dev->base + HIBMC_DP_TIMING_SYNC_CTRL);
+	} else {
+		hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_DPTX_GCTL0, BIT(10), 0);
+		writel(HIBMC_DP_SYNC_EN_MASK, dp_dev->base + HIBMC_DP_TIMING_SYNC_CTRL);
+		hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_VIDEO_CTRL, BIT(0), 0);
+		writel(HIBMC_DP_SYNC_EN_MASK, dp_dev->base + HIBMC_DP_TIMING_SYNC_CTRL);
+	}
+
+	msleep(50);
+}
+
+int hibmc_dp_mode_set(struct hibmc_dp *dp, struct drm_display_mode *mode)
+{
+	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
+	int ret;
+
+	if (!dp_dev->link.status.channel_equalized) {
+		ret = hibmc_dp_link_training(dp_dev);
+		if (ret) {
+			drm_err(dp->drm_dev, "dp link training failed, ret: %d\n", ret);
+			return ret;
+		}
+	}
+
+	hibmc_dp_display_en(dp, false);
+	hibmc_dp_link_cfg(dp_dev, mode);
+
+	return 0;
+}
+
+void hibmc_dp_reset_link(struct hibmc_dp *dp)
+{
+	dp->dp_dev->link.status.clock_recovered = false;
+	dp->dp_dev->link.status.channel_equalized = false;
+}
+
+u8 hibmc_dp_get_link_rate(struct hibmc_dp *dp)
+{
+	return dp->dp_dev->link.cap.link_rate;
+}
+
+u8 hibmc_dp_get_lanes(struct hibmc_dp *dp)
+{
+	return dp->dp_dev->link.cap.lanes;
+}
+
+static const struct hibmc_dp_color_raw g_rgb_raw[] = {
+	{CBAR_COLOR_BAR, 0x000, 0x000, 0x000},
+	{CBAR_WHITE,     0xfff, 0xfff, 0xfff},
+	{CBAR_RED,       0xfff, 0x000, 0x000},
+	{CBAR_ORANGE,    0xfff, 0x800, 0x000},
+	{CBAR_YELLOW,    0xfff, 0xfff, 0x000},
+	{CBAR_GREEN,     0x000, 0xfff, 0x000},
+	{CBAR_CYAN,      0x000, 0x800, 0x800},
+	{CBAR_BLUE,      0x000, 0x000, 0xfff},
+	{CBAR_PURPLE,    0x800, 0x000, 0x800},
+	{CBAR_BLACK,     0x000, 0x000, 0x000},
+};
+
+void hibmc_dp_set_cbar(struct hibmc_dp *dp, const struct hibmc_dp_cbar_cfg *cfg)
+{
+	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
+	struct hibmc_dp_color_raw raw_data;
+
+	if (cfg->enable) {
+		hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, BIT(9),
+					 cfg->self_timing);
+		hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, GENMASK(8, 1),
+					 cfg->dynamic_rate);
+		if (cfg->pattern == CBAR_COLOR_BAR) {
+			hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, BIT(10), 0);
+		} else {
+			raw_data = g_rgb_raw[cfg->pattern];
+			drm_dbg_dp(dp->drm_dev, "r:%x g:%x b:%x\n", raw_data.r_value,
+				   raw_data.g_value, raw_data.b_value);
+			hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, BIT(10), 1);
+			hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, GENMASK(23, 12),
+						 raw_data.r_value);
+			hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL1, GENMASK(23, 12),
+						 raw_data.g_value);
+			hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL1, GENMASK(11, 0),
+						 raw_data.b_value);
+		}
+	}
+
+	hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, BIT(0), cfg->enable);
+	writel(HIBMC_DP_SYNC_EN_MASK, dp_dev->base + HIBMC_DP_TIMING_SYNC_CTRL);
+}
+
+bool hibmc_dp_check_hpd_status(struct hibmc_dp *dp, int exp_status)
+{
+	u32 status;
+	int ret;
+
+	ret = readl_poll_timeout(dp->dp_dev->base + HIBMC_DP_HPD_STATUS, status,
+				 FIELD_GET(HIBMC_DP_HPD_CUR_STATE, status) == exp_status,
+				 1000, 100000); /* DP spec says 100ms */
+	if (ret) {
+		drm_dbg_dp(dp->drm_dev, "wait hpd status timeout");
+		return false;
+	}
+
+	dp->dp_dev->hpd_status = exp_status;
+
+	return true;
+}

linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h

@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_KAPI_H
+#define DP_KAPI_H
+
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <drm/drm_device.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_print.h>
+#include <drm/display/drm_dp_helper.h>
+
+struct hibmc_dp_dev;
+
+enum hibmc_hpd_status {
+	HIBMC_HPD_OUT,
+	HIBMC_HPD_IN,
+};
+
+enum hibmc_dp_cbar_pattern {
+	CBAR_COLOR_BAR,
+	CBAR_WHITE,
+	CBAR_RED,
+	CBAR_ORANGE,
+	CBAR_YELLOW,
+	CBAR_GREEN,
+	CBAR_CYAN,
+	CBAR_BLUE,
+	CBAR_PURPLE,
+	CBAR_BLACK,
+};
+
+struct hibmc_dp_color_raw {
+	enum hibmc_dp_cbar_pattern pattern;
+	u32 r_value;
+	u32 g_value;
+	u32 b_value;
+};
+
+struct hibmc_dp_cbar_cfg {
+	u8 enable;
+	u8 self_timing;
+	u8 dynamic_rate; /* 0:static, 1-255(frame):dynamic */
+	enum hibmc_dp_cbar_pattern pattern;
+};
+
+struct hibmc_dp {
+	struct hibmc_dp_dev *dp_dev;
+	struct drm_device *drm_dev;
+	struct drm_encoder encoder;
+	struct drm_connector connector;
+	void __iomem *mmio;
+	struct drm_dp_aux aux;
+	struct hibmc_dp_cbar_cfg cfg;
+	u32 irq_status;
+	int phys_status;
+};
+
+int hibmc_dp_hw_init(struct hibmc_dp *dp);
+int hibmc_dp_mode_set(struct hibmc_dp *dp, struct drm_display_mode *mode);
+void hibmc_dp_display_en(struct hibmc_dp *dp, bool enable);
+void hibmc_dp_set_cbar(struct hibmc_dp *dp, const struct hibmc_dp_cbar_cfg *cfg);
+void hibmc_dp_reset_link(struct hibmc_dp *dp);
+void hibmc_dp_hpd_cfg(struct hibmc_dp *dp);
+void hibmc_dp_enable_int(struct hibmc_dp *dp);
+void hibmc_dp_disable_int(struct hibmc_dp *dp);
+bool hibmc_dp_check_hpd_status(struct hibmc_dp *dp, int exp_status);
+u8 hibmc_dp_get_link_rate(struct hibmc_dp *dp);
+u8 hibmc_dp_get_lanes(struct hibmc_dp *dp);
+
+#endif

linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c

@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2024 Hisilicon Limited.
+
+#include <linux/delay.h>
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+#include "dp_comm.h"
+#include "dp_reg.h"
+
+#define HIBMC_EQ_MAX_RETRY 5
+
+static inline int hibmc_dp_get_serdes_rate_cfg(struct hibmc_dp_dev *dp)
+{
+	switch (dp->link.cap.link_rate) {
+	case DP_LINK_BW_1_62:
+		return DP_SERDES_BW_1_62;
+	case DP_LINK_BW_2_7:
+		return DP_SERDES_BW_2_7;
+	case DP_LINK_BW_5_4:
+		return DP_SERDES_BW_5_4;
+	case DP_LINK_BW_8_1:
+		return DP_SERDES_BW_8_1;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int hibmc_dp_link_training_configure(struct hibmc_dp_dev *dp)
+{
+	u8 buf[2];
+	int ret;
+
+	/* DP 2 lane */
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_PHYIF_CTRL0, HIBMC_DP_CFG_LANE_DATA_EN,
+				 dp->link.cap.lanes == 0x2 ? 0x3 : 0x1);
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_DPTX_GCTL0, HIBMC_DP_CFG_PHY_LANE_NUM,
+				 dp->link.cap.lanes == 0x2 ? 0x1 : 0);
+
+	/* enhanced frame */
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CTRL, HIBMC_DP_CFG_STREAM_FRAME_MODE, 0x1);
+
+	/* set rate and lane count */
+	buf[0] = dp->link.cap.link_rate;
+	buf[1] = DP_LANE_COUNT_ENHANCED_FRAME_EN | dp->link.cap.lanes;
+	ret = drm_dp_dpcd_write(dp->aux, DP_LINK_BW_SET, buf, sizeof(buf));
+	if (ret != sizeof(buf)) {
+		drm_dbg_dp(dp->dev, "dp aux write link rate and lanes failed, ret: %d\n", ret);
+		return ret >= 0 ? -EIO : ret;
+	}
+
+	/* set 8b/10b and downspread */
+	buf[0] = DP_SPREAD_AMP_0_5;
+	buf[1] = DP_SET_ANSI_8B10B;
+	ret = drm_dp_dpcd_write(dp->aux, DP_DOWNSPREAD_CTRL, buf, sizeof(buf));
+	if (ret != sizeof(buf)) {
+		drm_dbg_dp(dp->dev, "dp aux write 8b/10b and downspread failed, ret: %d\n", ret);
+		return ret >= 0 ? -EIO : ret;
+	}
+
+	return 0;
+}
+
+static int hibmc_dp_link_set_pattern(struct hibmc_dp_dev *dp, int pattern)
+{
+	int ret;
+	u8 val;
+	u8 buf;
+
+	buf = (u8)pattern;
+	if (pattern != DP_TRAINING_PATTERN_DISABLE && pattern != DP_TRAINING_PATTERN_4) {
+		buf |= DP_LINK_SCRAMBLING_DISABLE;
+		hibmc_dp_reg_write_field(dp, HIBMC_DP_PHYIF_CTRL0, HIBMC_DP_CFG_SCRAMBLE_EN, 0x1);
+	} else {
+		hibmc_dp_reg_write_field(dp, HIBMC_DP_PHYIF_CTRL0, HIBMC_DP_CFG_SCRAMBLE_EN, 0);
+	}
+
+	switch (pattern) {
+	case DP_TRAINING_PATTERN_DISABLE:
+		val = 0;
+		break;
+	case DP_TRAINING_PATTERN_1:
+		val = 1;
+		break;
+	case DP_TRAINING_PATTERN_2:
+		val = 2;
+		break;
+	case DP_TRAINING_PATTERN_3:
+		val = 3;
+		break;
+	case DP_TRAINING_PATTERN_4:
+		val = 4;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	hibmc_dp_reg_write_field(dp, HIBMC_DP_PHYIF_CTRL0, HIBMC_DP_CFG_PAT_SEL, val);
+
+	ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_PATTERN_SET, &buf, sizeof(buf));
+	if (ret != sizeof(buf)) {
+		drm_dbg_dp(dp->dev, "dp aux write training pattern set failed\n");
+		return ret >= 0 ? -EIO : ret;
+	}
+
+	return 0;
+}
+
+static int hibmc_dp_link_training_cr_pre(struct hibmc_dp_dev *dp)
+{
+	u8 *train_set = dp->link.train_set;
+	int ret;
+	u8 i;
+
+	ret = hibmc_dp_link_training_configure(dp);
+	if (ret)
+		return ret;
+
+	ret = hibmc_dp_link_set_pattern(dp, DP_TRAINING_PATTERN_1);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < dp->link.cap.lanes; i++)
+		train_set[i] = DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
+
+	ret = hibmc_dp_serdes_set_tx_cfg(dp, dp->link.train_set);
+	if (ret)
+		return ret;
+
+	ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET, train_set, dp->link.cap.lanes);
+	if (ret != dp->link.cap.lanes) {
+		drm_dbg_dp(dp->dev, "dp aux write training lane set failed\n");
+		return ret >= 0 ? -EIO : ret;
+	}
+
+	return 0;
+}
+
+static bool hibmc_dp_link_get_adjust_train(struct hibmc_dp_dev *dp,
+					   u8 lane_status[DP_LINK_STATUS_SIZE])
+{
+	u8 train_set[HIBMC_DP_LANE_NUM_MAX] = {0};
+	u8 lane;
+
+	for (lane = 0; lane < dp->link.cap.lanes; lane++)
+		train_set[lane] = drm_dp_get_adjust_request_voltage(lane_status, lane) |
+				  drm_dp_get_adjust_request_pre_emphasis(lane_status, lane);
+
+	if (memcmp(dp->link.train_set, train_set, HIBMC_DP_LANE_NUM_MAX)) {
+		memcpy(dp->link.train_set, train_set, HIBMC_DP_LANE_NUM_MAX);
+		return true;
+	}
+
+	return false;
+}
+
+static int hibmc_dp_link_reduce_rate(struct hibmc_dp_dev *dp)
+{
+	int ret;
+
+	switch (dp->link.cap.link_rate) {
+	case DP_LINK_BW_2_7:
+		dp->link.cap.link_rate = DP_LINK_BW_1_62;
+		break;
+	case DP_LINK_BW_5_4:
+		dp->link.cap.link_rate = DP_LINK_BW_2_7;
+		break;
+	case DP_LINK_BW_8_1:
+		dp->link.cap.link_rate = DP_LINK_BW_5_4;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = hibmc_dp_get_serdes_rate_cfg(dp);
+	if (ret < 0)
+		return ret;
+
+	return hibmc_dp_serdes_rate_switch(ret, dp);
+}
+
+static inline int hibmc_dp_link_reduce_lane(struct hibmc_dp_dev *dp)
+{
+	switch (dp->link.cap.lanes) {
+	case 0x2:
+		dp->link.cap.lanes--;
+		drm_dbg_dp(dp->dev, "dp link training reduce to 1 lane\n");
+		break;
+	case 0x1:
+		drm_err(dp->dev, "dp link training reduce lane failed, already reach minimum\n");
+		return -EIO;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
+{
+	u8 lane_status[DP_LINK_STATUS_SIZE] = {0};
+	bool level_changed;
+	u32 voltage_tries;
+	u32 cr_tries;
+	int ret;
+
+	/*
+	 * DP 1.4 spec define 10 for maxtries value, for pre DP 1.4 version set a limit of 80
+	 * (4 voltage levels x 4 preemphasis levels x 5 identical voltage retries)
+	 */
+
+	voltage_tries = 1;
+	for (cr_tries = 0; cr_tries < 80; cr_tries++) {
+		drm_dp_link_train_clock_recovery_delay(dp->aux, dp->dpcd);
+
+		ret = drm_dp_dpcd_read_link_status(dp->aux, lane_status);
+		if (ret) {
+			drm_err(dp->dev, "Get lane status failed\n");
+			return ret;
+		}
+
+		if (drm_dp_clock_recovery_ok(lane_status, dp->link.cap.lanes)) {
+			drm_dbg_dp(dp->dev, "dp link training cr done\n");
+			dp->link.status.clock_recovered = true;
+			return 0;
+		}
+
+		if (voltage_tries == 5) {
+			drm_dbg_dp(dp->dev, "same voltage tries 5 times\n");
+			dp->link.status.clock_recovered = false;
+			return 0;
+		}
+
+		level_changed = hibmc_dp_link_get_adjust_train(dp, lane_status);
+
+		ret = hibmc_dp_serdes_set_tx_cfg(dp, dp->link.train_set);
+		if (ret)
+			return ret;
+
+		ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET, dp->link.train_set,
+					dp->link.cap.lanes);
+		if (ret != dp->link.cap.lanes) {
+			drm_dbg_dp(dp->dev, "Update link training failed\n");
+			return ret >= 0 ? -EIO : ret;
+		}
+
+		voltage_tries = level_changed ? 1 : voltage_tries + 1;
+	}
+
+	drm_err(dp->dev, "dp link training clock recovery 80 times failed\n");
+	dp->link.status.clock_recovered = false;
+
+	return 0;
+}
+
+static int hibmc_dp_link_training_channel_eq(struct hibmc_dp_dev *dp)
+{
+	u8 lane_status[DP_LINK_STATUS_SIZE] = {0};
+	u8 eq_tries;
+	int ret;
+
+	ret = hibmc_dp_link_set_pattern(dp, DP_TRAINING_PATTERN_2);
+	if (ret)
+		return ret;
+
+	for (eq_tries = 0; eq_tries < HIBMC_EQ_MAX_RETRY; eq_tries++) {
+		drm_dp_link_train_channel_eq_delay(dp->aux, dp->dpcd);
+
+		ret = drm_dp_dpcd_read_link_status(dp->aux, lane_status);
+		if (ret) {
+			drm_err(dp->dev, "get lane status failed\n");
+			break;
+		}
+
+		if (!drm_dp_clock_recovery_ok(lane_status, dp->link.cap.lanes)) {
+			drm_dbg_dp(dp->dev, "clock recovery check failed\n");
+			drm_dbg_dp(dp->dev, "cannot continue channel equalization\n");
+			dp->link.status.clock_recovered = false;
+			break;
+		}
+
+		if (drm_dp_channel_eq_ok(lane_status, dp->link.cap.lanes)) {
+			dp->link.status.channel_equalized = true;
+			drm_dbg_dp(dp->dev, "dp link training eq done\n");
+			break;
+		}
+
+		hibmc_dp_link_get_adjust_train(dp, lane_status);
+
+		ret = hibmc_dp_serdes_set_tx_cfg(dp, dp->link.train_set);
+		if (ret)
+			return ret;
+
+		ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET,
+					dp->link.train_set, dp->link.cap.lanes);
+		if (ret != dp->link.cap.lanes) {
+			drm_dbg_dp(dp->dev, "Update link training failed\n");
+			ret = (ret >= 0) ? -EIO : ret;
+			break;
+		}
+	}
+
+	if (eq_tries == HIBMC_EQ_MAX_RETRY)
+		drm_err(dp->dev, "channel equalization failed %u times\n", eq_tries);
+
+	hibmc_dp_link_set_pattern(dp, DP_TRAINING_PATTERN_DISABLE);
+
+	return ret < 0 ? ret : 0;
+}
+
+static int hibmc_dp_link_downgrade_training_cr(struct hibmc_dp_dev *dp)
+{
+	if (hibmc_dp_link_reduce_rate(dp))
+		return hibmc_dp_link_reduce_lane(dp);
+
+	return 0;
+}
+
+static int hibmc_dp_link_downgrade_training_eq(struct hibmc_dp_dev *dp)
+{
+	if ((dp->link.status.clock_recovered && !dp->link.status.channel_equalized)) {
+		if (!hibmc_dp_link_reduce_lane(dp))
+			return 0;
+	}
+
+	return hibmc_dp_link_reduce_rate(dp);
+}
+
+void hibmc_dp_update_caps(struct hibmc_dp_dev *dp)
+{
+	dp->link.cap.link_rate = dp->dpcd[DP_MAX_LINK_RATE];
+	if (dp->link.cap.link_rate > DP_LINK_BW_8_1 || !dp->link.cap.link_rate)
+		dp->link.cap.link_rate = DP_LINK_BW_8_1;
+
+	dp->link.cap.lanes = dp->dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
+	if (dp->link.cap.lanes > HIBMC_DP_LANE_NUM_MAX)
+		dp->link.cap.lanes = HIBMC_DP_LANE_NUM_MAX;
+}
+
+int hibmc_dp_link_training(struct hibmc_dp_dev *dp)
+{
+	struct hibmc_dp_link *link = &dp->link;
+	int ret;
+
+	ret = drm_dp_read_dpcd_caps(dp->aux, dp->dpcd);
+	if (ret)
+		drm_err(dp->dev, "dp aux read dpcd failed, ret: %d\n", ret);
+
+	hibmc_dp_update_caps(dp);
+
+	ret = hibmc_dp_get_serdes_rate_cfg(dp);
+	if (ret < 0)
+		return ret;
+
+	ret = hibmc_dp_serdes_rate_switch(ret, dp);
+	if (ret)
+		return ret;
+
+	while (true) {
+		ret = hibmc_dp_link_training_cr_pre(dp);
+		if (ret)
+			goto err;
+
+		ret = hibmc_dp_link_training_cr(dp);
+		if (ret)
+			goto err;
+
+		if (!link->status.clock_recovered) {
+			ret = hibmc_dp_link_downgrade_training_cr(dp);
+			if (ret)
+				goto err;
+			continue;
+		}
+
+		ret = hibmc_dp_link_training_channel_eq(dp);
+		if (ret)
+			goto err;
+
+		if (!link->status.channel_equalized) {
+			ret = hibmc_dp_link_downgrade_training_eq(dp);
+			if (ret)
+				goto err;
+			continue;
+		}
+
+		return 0;
+	}
+
+err:
+	hibmc_dp_link_set_pattern(dp, DP_TRAINING_PATTERN_DISABLE);
+
+	return ret;
+}

linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h

@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_REG_H
+#define DP_REG_H
+
+#define HIBMC_DP_AUX_CMD_ADDR			0x50
+
+#define HIBMC_DP_AUX_WR_DATA0			0x54
+#define HIBMC_DP_AUX_WR_DATA1			0x58
+#define HIBMC_DP_AUX_WR_DATA2			0x5c
+#define HIBMC_DP_AUX_WR_DATA3			0x60
+#define HIBMC_DP_AUX_RD_DATA0			0x64
+
+#define HIBMC_DP_AUX_REQ			0x74
+#define HIBMC_DP_CFG_AUX_REQ			BIT(0)
+#define HIBMC_DP_CFG_AUX_SYNC_LEN_SEL		BIT(1)
+#define HIBMC_DP_CFG_AUX_TIMER_TIMEOUT		BIT(2)
+#define HIBMC_DP_CFG_AUX_MIN_PULSE_NUM		GENMASK(13, 9)
+
+#define HIBMC_DP_AUX_STATUS			0x78
+#define HIBMC_DP_CFG_AUX_TIMEOUT		BIT(0)
+#define HIBMC_DP_CFG_AUX_STATUS			GENMASK(11, 4)
+#define HIBMC_DP_CFG_AUX_READY_DATA_BYTE	GENMASK(16, 12)
+#define HIBMC_DP_CFG_AUX			GENMASK(24, 17)
+
+#define HIBMC_DP_HPD_STATUS			0x98
+#define HIBMC_DP_HPD_CUR_STATE		GENMASK(7, 4)
+
+#define HIBMC_DP_PHYIF_CTRL0			0xa0
+#define HIBMC_DP_CFG_SCRAMBLE_EN		BIT(0)
+#define HIBMC_DP_CFG_PAT_SEL			GENMASK(7, 4)
+#define HIBMC_DP_CFG_LANE_DATA_EN		GENMASK(11, 8)
+
+#define HIBMC_DP_VIDEO_CTRL			0x100
+#define HIBMC_DP_CFG_STREAM_RGB_ENABLE		BIT(1)
+#define HIBMC_DP_CFG_STREAM_VIDEO_MAPPING	GENMASK(5, 2)
+#define HIBMC_DP_CFG_STREAM_FRAME_MODE		BIT(6)
+#define HIBMC_DP_CFG_STREAM_HSYNC_POLARITY	BIT(7)
+#define HIBMC_DP_CFG_STREAM_VSYNC_POLARITY	BIT(8)
+
+#define HIBMC_DP_VIDEO_CONFIG0			0x104
+#define HIBMC_DP_CFG_STREAM_HACTIVE		GENMASK(31, 16)
+#define HIBMC_DP_CFG_STREAM_HBLANK		GENMASK(15, 0)
+
+#define HIBMC_DP_VIDEO_CONFIG1			0x108
+#define HIBMC_DP_CFG_STREAM_VACTIVE		GENMASK(31, 16)
+#define HIBMC_DP_CFG_STREAM_VBLANK		GENMASK(15, 0)
+
+#define HIBMC_DP_VIDEO_CONFIG2			0x10c
+#define HIBMC_DP_CFG_STREAM_HSYNC_WIDTH		GENMASK(15, 0)
+
+#define HIBMC_DP_VIDEO_CONFIG3			0x110
+#define HIBMC_DP_CFG_STREAM_VSYNC_WIDTH		GENMASK(15, 0)
+#define HIBMC_DP_CFG_STREAM_VFRONT_PORCH	GENMASK(31, 16)
+
+#define HIBMC_DP_VIDEO_PACKET			0x114
+#define HIBMC_DP_CFG_STREAM_TU_SYMBOL_SIZE	GENMASK(5, 0)
+#define HIBMC_DP_CFG_STREAM_TU_SYMBOL_FRAC_SIZE	GENMASK(9, 6)
+#define HIBMC_DP_CFG_STREAM_SYNC_CALIBRATION	GENMASK(31, 20)
+
+#define HIBMC_DP_VIDEO_MSA0			0x118
+#define HIBMC_DP_CFG_STREAM_VSTART		GENMASK(31, 16)
+#define HIBMC_DP_CFG_STREAM_HSTART		GENMASK(15, 0)
+
+#define HIBMC_DP_VIDEO_MSA1			0x11c
+#define HIBMC_DP_VIDEO_MSA2			0x120
+
+#define HIBMC_DP_VIDEO_HORIZONTAL_SIZE		0X124
+#define HIBMC_DP_CFG_STREAM_HTOTAL_SIZE		GENMASK(31, 16)
+#define HIBMC_DP_CFG_STREAM_HBLANK_SIZE		GENMASK(15, 0)
+
+#define HIBMC_DP_COLOR_BAR_CTRL			0x260
+#define HIBMC_DP_COLOR_BAR_CTRL1		0x264
+
+#define HIBMC_DP_TIMING_GEN_CONFIG0		0x26c
+#define HIBMC_DP_CFG_TIMING_GEN0_HACTIVE	GENMASK(31, 16)
+#define HIBMC_DP_CFG_TIMING_GEN0_HBLANK		GENMASK(15, 0)
+
+#define HIBMC_DP_TIMING_GEN_CONFIG2		0x274
+#define HIBMC_DP_CFG_TIMING_GEN0_VACTIVE	GENMASK(31, 16)
+#define HIBMC_DP_CFG_TIMING_GEN0_VBLANK		GENMASK(15, 0)
+
+#define HIBMC_DP_TIMING_GEN_CONFIG3		0x278
+#define HIBMC_DP_CFG_TIMING_GEN0_VFRONT_PORCH	GENMASK(31, 16)
+
+#define HIBMC_DP_HDCP_CFG			0x600
+
+#define HIBMC_DP_DPTX_RST_CTRL			0x700
+#define HIBMC_DP_CFG_AUX_RST_N			BIT(4)
+
+#define HIBMC_DP_DPTX_CLK_CTRL			0x704
+
+#define HIBMC_DP_DPTX_GCTL0			0x708
+#define HIBMC_DP_CFG_PHY_LANE_NUM		GENMASK(2, 1)
+
+#define HIBMC_DP_INTR_ENABLE			0x720
+#define HIBMC_DP_INTR_ORIGINAL_STATUS		0x728
+
+#define HIBMC_DP_TIMING_MODEL_CTRL		0x884
+#define HIBMC_DP_CFG_PIXEL_NUM_TIMING_MODE_SEL1	GENMASK(31, 16)
+
+#define HIBMC_DP_TIMING_SYNC_CTRL		0xFF0
+
+#define HIBMC_DP_INTSTAT			0x1e0724
+#define HIBMC_DP_INTCLR				0x1e0728
+
+/* dp serdes reg */
+#define HIBMC_DP_HOST_OFFSET		0x10000
+#define HIBMC_DP_LANE0_RATE_OFFSET	0x4
+#define HIBMC_DP_LANE1_RATE_OFFSET	0xc
+#define HIBMC_DP_LANE_STATUS_OFFSET	0x10
+#define HIBMC_DP_PMA_LANE0_OFFSET	0x18
+#define HIBMC_DP_PMA_LANE1_OFFSET	0x1c
+#define HIBMC_DP_HOST_SERDES_CTRL	0x1f001c
+#define HIBMC_DP_PMA_TXDEEMPH		GENMASK(18, 1)
+#define DP_SERDES_DONE			0x3
+
+/* dp serdes TX-Deempth Configuration */
+#define DP_SERDES_VOL0_PRE0		0x280
+#define DP_SERDES_VOL0_PRE1		0x2300
+#define DP_SERDES_VOL0_PRE2		0x53c0
+#define DP_SERDES_VOL0_PRE3		0x8400
+#define DP_SERDES_VOL1_PRE0		0x380
+#define DP_SERDES_VOL1_PRE1		0x3440
+#define DP_SERDES_VOL1_PRE2		0x6480
+#define DP_SERDES_VOL2_PRE0		0x4c1
+#define DP_SERDES_VOL2_PRE1		0x4500
+#define DP_SERDES_VOL3_PRE0		0x600
+#define DP_SERDES_BW_8_1		0x3
+#define DP_SERDES_BW_5_4		0x2
+#define DP_SERDES_BW_2_7		0x1
+#define DP_SERDES_BW_1_62		0x0
+
+#endif

linux-7.2.3/drivers/gpu/drm/hisilicon/hibmc/dp/dp_serdes.c

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2025 Hisilicon Limited.
+
+#include <linux/delay.h>
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+#include "dp_comm.h"
+#include "dp_config.h"
+#include "dp_reg.h"
+
+int hibmc_dp_serdes_set_tx_cfg(struct hibmc_dp_dev *dp, u8 train_set[HIBMC_DP_LANE_NUM_MAX])
+{
+	static const u32 serdes_tx_cfg[4][4] = { {DP_SERDES_VOL0_PRE0, DP_SERDES_VOL0_PRE1,
+						  DP_SERDES_VOL0_PRE2, DP_SERDES_VOL0_PRE3},
+						 {DP_SERDES_VOL1_PRE0, DP_SERDES_VOL1_PRE1,
+						  DP_SERDES_VOL1_PRE2}, {DP_SERDES_VOL2_PRE0,
+						  DP_SERDES_VOL2_PRE1}, {DP_SERDES_VOL3_PRE0}};
+	int cfg[2];
+	int i;
+
+	for (i = 0; i < HIBMC_DP_LANE_NUM_MAX; i++) {
+		cfg[i] = serdes_tx_cfg[FIELD_GET(DP_TRAIN_VOLTAGE_SWING_MASK, train_set[i])]
+				      [FIELD_GET(DP_TRAIN_PRE_EMPHASIS_MASK, train_set[i])];
+		if (!cfg[i])
+			return -EINVAL;
+
+		/* lane1 offset is 4 */
+		writel(FIELD_PREP(HIBMC_DP_PMA_TXDEEMPH, cfg[i]),
+		       dp->serdes_base + HIBMC_DP_PMA_LANE0_OFFSET + i * 4);
+	}
+
+	usleep_range(300, 500);
+
+	if (readl(dp->serdes_base + HIBMC_DP_LANE_STATUS_OFFSET) != DP_SERDES_DONE) {
+		drm_dbg_dp(dp->dev, "dp serdes cfg failed\n");
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+int hibmc_dp_serdes_rate_switch(u8 rate, struct hibmc_dp_dev *dp)
+{
+	writel(rate, dp->serdes_base + HIBMC_DP_LANE0_RATE_OFFSET);
+	writel(rate, dp->serdes_base + HIBMC_DP_LANE1_RATE_OFFSET);
+
+	usleep_range(300, 500);
+
+	if (readl(dp->serdes_base + HIBMC_DP_LANE_STATUS_OFFSET) != DP_SERDES_DONE) {
+		drm_dbg_dp(dp->dev, "dp serdes rate switching failed\n");
+		return -EAGAIN;
+	}
+
+	if (rate < DP_SERDES_BW_8_1)
+		drm_dbg_dp(dp->dev, "reducing serdes rate to :%d\n",
+			   rate ? rate * HIBMC_DP_LINK_RATE_CAL * 10 : 162);
+
+	return 0;
+}
+
+int hibmc_dp_serdes_init(struct hibmc_dp_dev *dp)
+{
+	dp->serdes_base = dp->base + HIBMC_DP_HOST_OFFSET;
+
+	writel(FIELD_PREP(HIBMC_DP_PMA_TXDEEMPH, DP_SERDES_VOL0_PRE0),
+	       dp->serdes_base + HIBMC_DP_PMA_LANE0_OFFSET);
+	writel(FIELD_PREP(HIBMC_DP_PMA_TXDEEMPH, DP_SERDES_VOL0_PRE0),
+	       dp->serdes_base + HIBMC_DP_PMA_LANE1_OFFSET);
+
+	return hibmc_dp_serdes_rate_switch(DP_SERDES_BW_8_1, dp);
+}